Parking lock mechanism

Abstract

A parking lock mechanism comprises: a parking gear; a plate-shaped parking pawl provided with a lock claw; and a cam mechanism including a cam in contact with the parking pawl and moving the cam in parallel with a rotation axis of the parking gear to pivot the parking pawl, the parking pawl having a plate thickness made larger in a portion provided with the lock claw as compared to the other portions of the parking pawl. The portion provided with the lock claw of the parking pawl has a surface that is formed on the front side in a movement direction of the cam at the time of switching from the non-lock state to the lock state and that bulges in the movement direction.

What is claimed is: 
     
         1 . A parking lock mechanism comprising:
 a parking gear integrally disposed on a rotating member mechanically coupled to a drive wheel;   a plate-shaped parking pawl provided with a lock claw configured to mesh with the parking gear and pivoted for switching between a lock state in which the lock claw is meshed with the parking gear and a non-lock state in which meshing between the lock claw and the parking gear is released; and   a cam mechanism including a cam in contact with the parking pawl and moving the cam in parallel with a rotation axis of the parking gear to pivot the parking pawl,   the parking pawl having a plate thickness made larger in a portion provided with the lock claw as compared to the other portions of the parking pawl, wherein   the portion provided with the lock claw of the parking pawl has a surface that is formed on the front side in a movement direction of the cam at the time of switching from the non-lock state to the lock state and that bulges in the movement direction.   
     
     
         2 . The parking lock mechanism according to  claim 1 , further comprising a return spring urging the parking pawl to the non-lock state side. 
     
     
         3 . The parking lock mechanism according to  claim 1 , wherein
 the cam is provided with a conical tapered surface, and wherein   a taper-shaped notch configured to be brought into contact with the tapered surface of the cam is formed on a surface of the parking pawl located on the rear side in the movement direction of the cam at the time of switching from the non-lock state to the lock state.   
     
     
         4 . The parking lock mechanism according to  claim 2 , wherein
 the cam is provided with a conical tapered surface, and wherein   a taper-shaped notch configured to be brought into contact with the tapered surface of the cam is formed on a surface of the parking pawl located on the rear side in the movement direction of the cam at the time of switching from the non-lock state to the lock state.   
     
     
         5 . The parking lock mechanism according to  claim 1 , wherein
 the cam mechanism includes a parking rod moving parallel to the rotation axis of the parking gear, and a cam spring urging the cam toward a leading end of the parking rod, wherein   the cam is attached to the parking rod,   the cam is inserted through the parking rod relatively movably in an axial direction with respect to the parking rod and is urged toward the leading end of the parking rod by the cam spring, and   the leading end of the parking rod is provided with a large diameter portion coming into contact with the cam and restricting the movement of the cam.   
     
     
         6 . The parking lock mechanism according to  claim 2 , wherein
 the cam mechanism includes a parking rod moving parallel to the rotation axis of the parking gear, and a cam spring urging the cam toward a leading end of the parking rod, wherein   the cam is attached to the parking rod,   the cam is inserted through the parking rod relatively movably in an axial direction with respect to the parking rod and is urged toward the leading end of the parking rod by the cam spring, and   the leading end of the parking rod is provided with a large diameter portion coming into contact with the cam and restricting the movement of the cam.   
     
     
         7 . The parking lock mechanism according to  claim 3 , wherein
 the cam mechanism includes a parking rod moving parallel to the rotation axis of the parking gear, and a cam spring urging the cam toward a leading end of the parking rod, wherein   the cam is attached to the parking rod,   the cam is inserted through the parking rod relatively movably in an axial direction with respect to the parking rod and is urged toward the leading end of the parking rod by the cam spring, and   the leading end of the parking rod is provided with a large diameter portion coming into contact with the cam and restricting the movement of the cam.   
     
     
         8 . The parking lock mechanism according to  claim 4 , wherein
 the cam mechanism includes a parking rod moving parallel to the rotation axis of the parking gear, and a cam spring urging the cam toward a leading end of the parking rod, wherein   the cam is attached to the parking rod,   the cam is inserted through the parking rod relatively movably in an axial direction with respect to the parking rod and is urged toward the leading end of the parking rod by the cam spring, and   the leading end of the parking rod is provided with a large diameter portion coming into contact with the cam and restricting the movement of the cam.